The invention concerns a blister packaging machine comprising a forming station, in which a plurality of cup-shaped depressions can be formed into a bottom sheet, a filling station, in which a product can be filled into the cup-shaped depressions, and a downstream sealing station in which a cover sheet can be sealed onto the bottom sheet, wherein the filling station comprises a brush box which is disposed above the bottom sheet and which contains several rotary driven roller brushes disposed parallel and next to each other, the roller brushes being connected to a rotary drive which is accommodated in a drive gearbox disposed next to the brush box.
A blister packaging machine of conventional structure comprises a forming station, in which a plurality of cup-shaped depressions are formed into a bottom sheet which consists of plastic material or aluminum. A product, e.g. a pharmaceutical tablet, is inserted into each depression at a downstream filling station. After product supply, the bottom sheet is transported to a sealing station. A cover sheet is introduced directly before or within the sealing station and is disposed on the bottom sheet. The cover sheet is tightly sealed onto the bottom sheet within the sealing station using heat, thereby enclosing the product in the cup-shaped depression.
The forming station is usually operated in cycles and therefore discontinuously. The filling and sealing stations can also be operated in cycles or, alternatively, continuously, wherein conventional compensation means effect transfer between cyclical operation of the forming station and continuous operation of the filling and sealing stations.
The filling station comprises a brush box which contains a plurality of roller brushes which are disposed in a rotating fashion and are in mutual, close and parallel adjacency to each other, and extend transverse to the direction of motion of the bottom sheet. The brush box is disposed directly above the bottom sheet and the cup-shaped depressions are open in an upward direction, i.e. facing the brush box. A sufficient amount of product, e.g. a large number of tablets, is supplied to the upper side of the brush box. The brush box has the task of distributing the tablets over the bottom sheet passing below it, such that the tablets fall into the cup-shaped depressions of the bottom sheet. A drive gearbox is disposed next to the brush box, which accommodates a drive for rotating the roller brushes. Each roller brush usually has its own drive motor whose rotary or drive motion is transmitted to the associated roller brush by a shaft which penetrates through an opening in the wall of the drive gearbox.
The number and design of the roller brushes in the brush box depends on the type and size of the product to be filled in. Format change during operation of the blister packaging machine therefore requires dismounting the brush box and replacing it with another brush box of suitable structure. Towards this end, each roller brush shaft must be released from its respective drive motor. After installation of the new brush box, the new roller brush shafts must be re-connected to the drive motors. Alternatively, the drive motors are conventionally dismounted together with the roller brushes for product change when the brush box is replaced by another supply system. Such handling is time-consuming and expensive.
Since product dust or product chips are always produced in the region of the brush box, the above-mentioned brush box structure always bears the risk of having these particles penetrate into the coupling and the opening region of the drive shafts, thereby soiling it. During product change, these locations must be thoroughly cleaned to prevent residues of previously processed product from entering into the new product to be subsequently processed.
It is the underlying purpose of the invention to produce a blister packaging machine of the above-mentioned type, wherein the brush box can be replaced in a simple manner while reliably preventing brush box particles from entering into the drive gearbox.